The present invention relates to an automatic pneumatic gripper, especially to an automatic pneumatic gripper applied to a fixing post of a screen printing machine for arranging squeegees or scrapers under the fixing post.
Generally, a fixing member is used to assemble and fasten a squeegee/scraper on a fixing post of a printing head on a screen printing machine. Refer from FIG. 1 to FIG. 3, a clamping member 10 formed by a c-shaped clip 11 for clipping on a fixing post 30 of a printing head and a manual-operated bolt 12 threaded on top thereof. A projecting member is disposed on each side of a bottom of the clamping member 10 for clipping a top surface of a squeegee/scraper 32. While being rotated clockwise, the manual-operated bolt 12 moves downward and contacts with the top surface of the fixing rod 30 so that the c-shaped clip 11 relatively moves upward and further drives the top surface of the squeegee/scraper 32 to move upward to be attached and fixed on the bottom surface of the fixing post 30 to be in a fastened state, as shown in FIG. 2. Once the manual-operated bolt 12 is rotated counterclockwise, the top surface of the squeegee/scraper 32 moves downward to release from the bottom surface of the fixing post 30 to be in a released state, as shown in FIG. 3.
However, while assembling (or disassembling) the squeegee/scraper 32, the clamping member 10 is difficult to be sleeved (or released) from one end of the fixing post 30, as shown in FIG. 1 due to some structures of the printing machine such as the longer squeegee/scraper 32. The difficulties in sleeving/releasing of the clamping member 10 further bring difficulties in assembling/disassembling of the squeegee/scraper 32. As shown in FIG. 4 & FIG. 5, the fixing post 30 and the squeegee 31/scraper 32 respectively are disposed with at least one hole, corresponding to each other. By a bolt 20 inserting each hole and being fastened with a screw nut, the fixing post 30 and the squeegee 31/scraper 32 are fastened with each other. Yet the bolt 20 is used in a single position for fastening. When a longer squeegee 31/scraper 32 is used, thickness of the printed image may be uneven due to uneven force.